Understanding the metric system is easy if you know what base units means and what the prefixes are and how they are used. If you plan to travel the world, study science, or use this world and scientific standard as part of your daily life at home, then understanding the metric system is essential. The metric system was designed to make measuring things easier and universal.

Steps

Part 1

Understanding the Basics

1

Know how the base units work. In the metric system, each form of measurement has one base unit. The most common base units are:[1]

length - meter (m)

volume - liter (l)

mass - gram (g)

An easy way to remember the common base units is the mnemonic:
"My Large Giraffe,” where the first letter of each word represents a base unit: m ⇒ meter, l ⇒ liter, and g ⇒ gram: My Large Giraffe.

2

Understand multiples of ten. The metric system is a decimal system, meaning every unit gets bigger or smaller by multiples of ten: Smaller measurements are divided by ten; larger measurements are multiplied by ten.[2]

This means that if you move a decimal point within a measurement you change the unit size. For instance, if you move the decimal in 90,000 grams three places to the right, the equivalent measurement is expressed as 90 kilograms.

When converting a small unit to a larger unit, move the decimal to the left. When you are converting a larger unit to a smaller unit, move the decimal to the right.

3

Learn the common prefixes. The common prefixes are milli-,centi-, deci-, deka-, hecto-, and kilo-. In the metric system, you look at the prefix to see the size of the unit, while the base unit tells you what is being measured. For instance, if you are measuring mass, the base is grams. If you want to know the size, then you look at the prefix. When the prefix kilo- is used, it means that the size is 1,000 time larger than the base. A kilogram is 1,000 times larger than the base of 1 gram. [3]

4

Use the sentence “King Henry Doesn’t (Usually) Drink Chocolate Milk” to remember these prefixes. In this sentence, the first letter of each word represents a prefix while “Usually” represents unit or the base unit you are using. This sentence represents the prefixes in this order: kilo-, hecto-, deka-, unit, deci-, centi-, and milli-.[4]

Every step in this sentence is either ten times or one-tenth as much as the steps besides it. So if you used 5 kilometers (King) in the sentence you would have: 5 kilometers = 50 hectometers = 500 dekameters= 5000 meters = 50,000 decimeters = 500,000 centimeters = 5,000,000 millimeters.

5

Draw a diagram to help you remember. Drawing a diagram will not only help you remember, but will help you to understand the relationships between prefixes and base units. Draw a horizontal line. Then, draw seven vertical lines across the horizontal line. Write the first letter of the prefixes above each vertical line: K, H, D, U, D, C, and M. Beneath the vertical line with “U,” write the first letter for the most common units: meters, liters, and grams.

On the diagram, prefixes to the left of the base unit represent larger numbers, and prefixes to the right of the base unit represent smaller numbers.

Each space between the vertical marks to the left or right of the base unit represents a decimal. For example, if the base equaled 6500 meters and you wanted to convert that measurement into kilometers, you would count the lines between “K” and “M.” There are three spaces between “K” and “M.” This means that you would place the decimal three spaces to the left of 6500 meters, which would be 6.5 kilometers.

Part 2

Changing Your Thinking

1

Start thinking metrically. Try to use the metric system daily. Start measuring using the base units of the metric system. Learn how long a centimeter is, or how far away a meter is, or how much a gram weighs. It’s important to use the system in addition to memorizing the units and prefixes. Using the system reinforces your understanding.[5]

A great place to practice using the metric system is at the grocery store. Look at items that are measured in liters and grams. This will help you understand the quantities used in the metric system.

When you describe an object, use the metric system. Describe the weight in grams, the length in meters, and the volume in liters.

When you cook, measure using metric units. This will help you understand measuring items metrically.

2

Stop converting to non-metric units. By only using the metric system, you force yourself to rely on the metric system. There are many benefits to this. You will do less math, including no more fractions, and you will have to remember far less.

3

Understand the benefits. The metric system is used all over the world. The scientific community only uses the metric system. By knowing how it works, you will be able to navigate through many places and participate easier in discussions with people who only use the metric system.

Unlike the imperial system which uses many different terms for measurement - such as ounces, cups, pints, and quarts - the metric system uses one term, which makes it easier to remember and measure.[6]

There are only three countries that currently use the Imperial measurement system: Liberia, Myanmar, and the United States of America. Learning the metric system will help you navigate when you travel the world.